Field of the Invention
The present invention relates to an antenna system and method for selecting network connections according to priorities.
Description of the Related Art
The term “handoff (or handover)” in wireless communication refers to the process of transferring an ongoing call or data session from a channel associated with a network to another. The wireless networks typically involve Wireless Local Area Network (WLAN) and Wireless Wide Area Network (WWAN), where complimentary characteristics are provided, for example, fast speed, low cost, wide bandwidth and short-range access in the WLAN and slow speed, high cost, narrow bandwidth and long-range access in the WWAN. Laptops, tablets, personal digital assistants, cellular phones, smart phones and other mobile devices may be equipped with a wireless network interface to enable connections to both the WLAN and the WWAN.
Some of the mobile devices may be connected to the WLAN through access points such as routers, and may be adapted to operate in accordance with the IEEE 802.11 standards for communication in the 2.4, 3.6 and 5 GHz frequency bands. WLANs have become popular in recent years for the home or office use due to ease of installation and low cost or often free access. WWANs may be cellular telecommunication networks having multiple base stations, based on cellular network technologies such as Global Systems for Mobile Communication (GSM), General Packet Radio Service (GPRS), Code Division Multiple Access (CDMA), CDMA2000, Universal Mobile Telecommunication System (UMTS), and Enhanced Data Rates for GSM Evolution (EDGE). These cellular network technologies are offered regionally, nationwide and even globally by wireless service providers. Several different types of cells are served by base stations, such as femtocells, picocells, microcells and macrocells, providing different types of overage in the cellular network.
Since the WLAN access is generally provided at low cost or often free of charge, a user's preference may be to stay on a WLAN connection as long as possible. A communication scheme to allow for such a network selection preference may be referred to as the “WLAN-first scheme.” As new generations of handsets, laptops, tablets and other wireless communication devices become smaller and embedded with more applications, designing new types of antennas and associated air interface functions is becoming important. In particular, new capabilities that can lead to a QOS improvement are expected to be increasingly in high demand, including, for example, handoff schemes based on priorities involving cost, security, emergency and other considerations and user preferences.